PCB Build - Progress - Post your Pics here :-)

All information relating to the Alpha plus all the WIP threads etc.
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Icky
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Re: PCB Build - Progress - Post your Pics here :-)

Post by Icky »

Forgottenmyname wrote: Fri Sep 14, 2018 10:15 pm Ok so a brief update.

I've plugged the board into my bench power supply, just the two five volt and two 0 volt rails and recorded a current use of 440ma.

None of the components are even warm to touch after being on for 5 mins but no video as yet.
Snap - just done the same. - bench power supply drawing 460ma - components all cool to touch.
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PhilC
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Re: PCB Build - Progress - Post your Pics here :-)

Post by PhilC »

Ok, so far:

Reset circuit toggles cpu ok.
_Halt is high, so the cpu is running.
8mhz to you is stable.
16 and 32mhz at shifter seem good to me.
_AS at cpu has a square 1mhz signal and the datalines seem to all have the same 1mhz triangular signal.
MMU seems to be communicating ok with data on the MAD lines.

I'm willing to bet either I've miss soldered something on the rgb circuit or something is missing, as nothing really happening on the monitor plug.

Will dig out my old CRT tv tomorrow and see what that does.
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Re: PCB Build - Progress - Post your Pics here :-)

Post by PhilC »

Icky wrote: Sat Sep 15, 2018 9:46 pm
Snap - just done the same. - bench power supply drawing 460ma - components all cool to touch.
Cool, we can't be far off with similar figures.
Did you have no video either Icky?
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Re: PCB Build - Progress - Post your Pics here :-)

Post by alienkidmj12 »

this all sounds awesome, well done guys, been a bit busy but had a good read tonight :)
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Re: PCB Build - Progress - Post your Pics here :-)

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Forgottenmyname wrote: Sat Sep 15, 2018 9:58 pm Cool, we can't be far off with similar figures.
Did you have no video either Icky?
Hi - No video yet. The monitor did sense something at one point i.e. no-signal to a flicker, but I'm putting that down to just background noise as I have not seen it since.

Like you I will start looking tomorrow more closely with my scope
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Icky
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Re: PCB Build - Progress - Post your Pics here :-)

Post by Icky »

Forgottenmyname wrote: Sat Sep 15, 2018 9:58 pm Did you have no video either Icky?
And now I have life but no meaning :)

Not sure what I have here but I have output.

IMG_3044.png
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Re: PCB Build - Progress - Post your Pics here :-)

Post by BlankVector »

Exciting progress :D
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Re: PCB Build - Progress - Post your Pics here :-)

Post by alienkidmj12 »

i can see trees and sunset there, in the distance !! or you could actually say, waves washing up on the shoreline
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Re: PCB Build - Progress - Post your Pics here :-)

Post by exxos »

Does the floppy drive get accessed ?

Looks like a sync issue so far.. Even without tos running the video should be stable.. Its worth checking back from the monitor port to glue etc.. Don't assume I've wired the connector up right either ;)
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Re: PCB Build - Progress - Post your Pics here :-)

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exxos wrote: Sun Sep 16, 2018 12:11 am Does the floppy drive get accessed ?

Looks like a sync issue so far.. Even without tos running the video should be stable.. Its worth checking back from the monitor port to glue etc.. Don't assume I've wired the connector up right either ;)
I don't have the floppy connected at the moment.

But here is video of first boot. As you can see I get the black screen then it starts to go out of sync.


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